My car is a 4.2 XKR but here goes:

Standard "back box" still on:



And off, just requires bolts to the middle section pipes undone and hangers popped out of the rubber mounts:



New heatshield in place (old one had vanished somewhere along the line):



New box in place, refitting is the reverse of removal:



Lovely pipes, they didn't stay clean for long though:





First start!


And some revs:


That's the Elite RR rear silencer, already have the Spires "Stage 1" middle section with resonator deletes and a X-pipe.

 

Ooo, that'll do it. You mentioned your car was a 2009, but didn't list the year of the donor car. There's a lot of things won't cross the 4.2 / 5.0 barrier, sorry.

 

Original 4.2 XK back box.




4.2 XKR back box to install.




Side by side, mounting points are the same.




XK back box removed, original XK valence still in place




XK valence removed.




XKR valence installed.




XKR back box installed.

 

Once again, that's everyone for all of your insight. I was so excited to have his XKR back box (and a Jag that had a throaty rumble) that I never gave a thought to my '09 being a 4.2 vs. his '12 being a 5.0! Safe to assume no one has a 4.2 XKR back box for sale? Bummer! Oh well, life goes on!

 

There was one for sale in the 'marketplace', but don't know if it is still available:
https://www.jaguarforums.com/forum/p...-miles-157910/

 

In the event that I can't find a 4.2 XKR back box, does anyone know what the cost might be to have a muffler specialty shop adapt a 5.0 XKR back box to a 4.2 XK exhaust? More or less than $300? Thanks (as always).

 

I've been wrong before, but its got to be way less than $300.
Since you've got both boxes, you can check if the entrance pipes are the same diameter, if they are, that's one simplification. Then the question is, does only one, or do both pipes need to be modified? Maybe the e-diff only has a 'bulge' on one side? If they can cut and bend the existing 5.0 XKR pipes to fit the 4.2 pattern, that's a materials cost savings too.

 

Nothing is ever simple on a jaguar it seems...sigh

 

I am thinking a specialized X-pipe from the catalytic converters to the Rear back box with deletion of the 1 resonator would be best to solve 2 problems


1- connect the back box
2- MORE NOISE

 

Don't see why you couldn't modify the input pipes on the rear muffler. Even with stainless it shouldn't cost more than $200.

 

It's not.

 

As you may remember, Lothar52 was nice enough to give me the back box from his 2012 5.0 XKR, which he didn't need anymore because he recently bought an awesome Spires Stage 3 exhaust system.

I wanted to install his back box in place of my 2009 4.2 XK back box but his back box pipes didn't line up with my under-carriage exhaust pipes. The Forum recommended I take it to a specialty muffler shop, which I did today.

It only took them 40 minutes to fabricate the necessary connector pipes and they only charged me $65 labor. Summary ...

XKR back box ... free.
New XKR rear valance ... $35.
Labor to install both ... $65.
Total cost ... $100
Sound ... priceless!
Good friends ... rare and greatly appreciated!

 

Congrats! Great price for a ticket to the symphony!

 

What an absolute bargain I paid $600 plus a 3hr drive to collect mine !

 

It sounded awesome.. as soon as Snide pulled out and hit the gas you could hear a MUCH better sound coming from the car!! I felt compelled to follow in my 5.0 thumbs up out the window!!! . Not only does it sound better but I can not believe the difference going from 2-4 pipes makes in appearance looking at the XK from the back. It really is 1000x better looking. It really makes the car just LOOK SO MUCH MORE AGGRESSIVE. Fantastic Outcome!!

 

Anybody with a XK that wants a more aggressive look... wants a more aggressive sound.. a V8 sound in its own right amazing -- NA V8... get some straight back pipes from the converters to the back box, find out what valence Snide got from him, and get a 4 piper vs the 2 it came with! YOU WONT BE DISAPPOINTED... trust me

 

Where can you get that rear valance to accommodate the quad pipes for $50.00??

 

The part number is C2P8245 (they call it a Lower Extension). Google it, and you'll find it available at multiple places.

The cheapest I see right now is $35.61 at parts.com:

https://www.parts.com/index.cfm?fuse...del-LOWER-EXTN

For slightly more ($36.19):

Lower Extension | Genuine Jaguar | C2P8245

For me, the second option is a few cents cheaper, when you include shipping, so $48.32 (which is under $50) to my location.

Other dealers online are around $45-ish (not including shipping).

I just ordered another one, while they are still available, as I might want to modify it a bit (for a project that's been on hold for awhile).

 

Good find kj !

 

You are a beast! Thanks!!